Past

Pseudomyxoma peritonei (PMP) is a rare disease.1 The completeness of cytoreduction is an important prognostic factor for PMP because patients who experienced complete cytoreductive surgery (CCRS) had an 5-year survival rate of 85 % compared with those who had incomplete cytoreduction (IC).2 To date, no nomograms have been established to predict incomplete cytoreduction (IC) for patients with PMP.

Present

The current study developed a nomogram to predict IC for PMP patients. The study enrolled 144 PMP patients between 1 June 2013 and 22 November 2019. Logistic regression modeling identified four factors (sex, disease duration, anemia, and carbohydrate antigen 19-9 [CA 19-9]) that independently predict IC for PMP patients. The study then established a nomogram predicting IC, which demonstrated good predictive accuracy (C-index, 0.837; 95 % confidence interval, 0.764–0.894).3

Future

A former study found that an experienced radiologist could assess the total peritoneal cancer index (PCI) correctly on both computed tomography (CT) and magnetic resonance imaging (MRI) scans.4 The PCI is used to reflect tumor burden for PMP, and a higher PCI always denotes unresectable disease for PMP. Therefore, the PMP center requires not only experienced surgeons, but also experienced radiologists. In the future, the CT or MRI-PCI will be assessed in the prediction model. Finally, prospective and multi-institutional research should be conducted for external validation aimed at accurate prediction of cytoreducibility among PMP patients to establish preoperative plans.